The invention concerns a method and a device for numeric path control for electroerosion machines.
The processing of work pieces to achieve relatively difficult geometric figures, as for example a hyperboloid shape, must be done with the maximum possible precision of the existing surfaces as against the desired surfaces (actual surface, target surface). The surface precision of the work piece processed is in this instance defined by the course of an actual track curve on the surface in relation to a target track curve.
From European patent specification 0 062 074, it is known how to use an erosion wire the two guides of which are moved independently of each other. So that one does not have to feed in too many track points for the definition of the track curves for the guides, and thus indirectly for the target track curves, on the surface of the work piece, it is known how to determine the complete, desired track curve between given track points, with the help of a given function, by means of interpolation. According to the known art, the interpolation of the track curves is performed for the two guides of the wire electrode independent of each other; however, in both cases the nature or the interpolation, or, more precisely, the mathematical function, according to which the interpolation is made, is identical.
However, the measurement precision, and in particular the surface quality, of work pieces processed with the known machine, were found to be unsatisfactory.